* South African rand set for worst day in six weeks

* Record daily rise in virus cases in U.S., Brazil, India

* Spikes in cases in Asia dispel notion of the worst being over

By Shreyashi Sanyal

July 30 (Reuters) - The Russian rouble touched its lowest level in more than two months on Thursday, weakening along with most other emerging market currencies as record spikes in COVID-19 cases dashed optimism sparked overnight by a dovish U.S. Federal Reserve.

The rouble tumbled as much as 1.5% against the dollar to hit its lowest level since mid-May, while also touching its lowest since early April against the euro. South Africa's rand tumbled 1.3% and was on track for its worst day in six weeks.

Surging coronavirus infections in Asia have dispelled any notion that the region may be over the worst, with Australia and India reporting record daily infections on Thursday, Vietnam fretting over a new spike and North Korea urging vigilance.

The United States and Brazil also reported a record number of new deaths and confirmed cases.

Optimism sparked by the Fed faded, even after the U.S. central bank vowed to "do what we can, and for as long as it takes," to limit damage and boost growth. All eyes are now on the U.S. Republicans and Democrats, struggling to reach a deal to provide more aid.

"The Fed's decision on this also appeared to be an acknowledgment that current events are likely to remain largely out of their hands...," said Michael Hewson, chief market analyst at CMC Markets UK.

Future Fed action would be dependent not only on the overall course of the virus, but also on any further fiscal action from U.S. politicians, a factor which chair Jerome Powell made reference to in his post meeting press conference, Hewson added.

The Turkish lira showed some signs of steadying after four straight days of decline even as concerns lingered over depleted reserves and local demand for dollars.

Data showed Turkey's economic confidence index rebounded 11.8% month-on-month in July to 82.2 points, a third month of recovery from lows caused by coronavirus curbs.

Stocks in the developing world fell 0.2%, reversing gain made in early Asian trading, with Warsaw stocks leading declines.

Poland may reinstate quarantine measures for people returning home from some countries, a government spokesman said, after recent data showed a spike in coronavirus infections.

Johannesburg shares fell, with heavyweight diversified miner Anglo American shedding 1% on halving its interim dividend and said first- half profits fell 39% as lockdowns hit production.

For GRAPHIC on emerging market FX performance in 2020, see http://tmsnrt.rs/2egbfVh For GRAPHIC on MSCI emerging index performance in 2020, see https://tmsnrt.rs/2OusNdX

For TOP NEWS across emerging markets

For CENTRAL EUROPE market report, see

For TURKISH market report, see

For RUSSIAN market report, see (Reporting by Shreyashi Sanyal in Bengaluru; Editing by Rashmi Aich)